Japan Wants To Put A Giant Solar Farm In Space

Picture this: a giant solar power plant floating in space, gathering the sun’s energy with virtually no constraints from the weather, seasons or time of day, delivering a constant supply of green energy to Earth. Sound a little too Sci-Fi? Well, thanks to JAXA, the Japan Aerospace Exploration Agency, we could actually witness this incredible technology in just over a decade.

The idea of a space power plant has actually been around for a while. Back in 1968, American aerospace engineer Dr. Peter Glaser pioneered the space solar power concept and proposed the deployment of giant solar panels in space in order to generate microwaves that could be transmitted back to Earth to produce electricity. The concept sparked a lot of interest, even from NASA, but it came to a halt in the ‘80s because of the high costs involved. Japan, however, pursued the idea and is currently the world leader of the Space Solar Power Systems (SSPS) project.

This colossal satellite, hovering around 22,000 miles (36,000 kilometers) above Earth, would be several miles long and weigh a whopping 10,000 metric tons. These floating solar panels would actually be tethered to a station on the ground in order to keep the satellite at a fixed point in geostationary orbit. The proposed model also includes a set of mirrors that reflect the sun’s light onto the panels so that when the satellite is not facing the sun it can still receive sunlight.

And now for the really tricky part: getting all of that solar energy back to Earth so that we can use it. There are two possible ways that this could be achieved which involve converting the solar energy into either laser beams or microwaves, or perhaps even a combination of both, which would then be transmitted to a receiving facility (called a “rectenna” [rectifying antenna]) situated on Earth. Ground-based experiments are currently underway to discern which option would be most efficient.

These space based solar panels would be around 5-10 times more efficient than ground-based solar conversion systems. Furthermore, CO2 emissions will be low and will only come from the receiving facility. It’s predicted that SSPS will be able to process around 1 gigawatt of power, which is a similar amount to nuclear power stations.

Although Japan are the leading country with regards to making SSPS happen, in reality the costs will be so astronomical that it is likely contributions from other countries will be required before we see this behemoth space power station start to take shape. This concept may seem a little far-fetched, but JAXA believe they are getting tantalizingly close to turning this vision into a reality.